Muffler



H. F. DUBBEN AND F. B. EASTON.

MUFFLER.

APPLICATION FILED MARKH, 1920.

1,388,554, Patented Aug. 23, 1921.

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FVENTORS HARRY Duanw By FRANK 5. .CAs-ro/v.

A froze/v15 Y UNITED srAras nl'rau'r oFFicE.

namur r. minim amarmx n. aas'ron; oi NEW Yomr, n. Y,

To all whom it may com/em:

Be it known that we, HARRY F. DUBBnN and FRANK B. EASTON, citizens of the United States, and residents of New York, in the county of New York and State of New York, have invented certain new a-nd useful Improvements in Mufllers, of which the following is a specification.

Our invention relates to an lmproved mufller; particularly a muffler for treating .the exhaust gases of the engines'of' automobiles, aeroplanes, trucks and 'othermotor vehicles.

An object of our invention is to prov1de-a mufiler which is of simple construction and inexpensive to manufacture, and which is adapted both to deaden the sound of the escaping of the ack pressure created in the cylinders of the engine by the action of such gases.

A further object of our' invention is to provide a mufiler by which the exhaust gases of an engine can be expandedand allowed to escape freely and noiselessly into the atmosphere, without substantially changing the direction of flow given to them in the exhaust pipe which conducts them away from the engine.

Another object ofour invention is to provide a muffler which is. adapted. to permit part of the exhaust gases of an engine to escape into the atmosphere directly from-the dischar end of the exhaust pipe and the remain er from an outlet which is supplen entary to the discharge end of the exhaust P lhe above and other objects and advantages of our invention are clearly set forth in the following description, taken in connection with the accompanying drawings. This disclosure, however, is to be construed as explanatory only, and embodiments of our invention other than that actually shown herein may be made to the full extent of the general meanings of the terms in which the claims appended hereto, and defining our invention, are expressed.

In the drawings:

Figure 1 is a side view flprincipally in longitudinal section of a mu er constructed according to our invention;

Fi 2 isa sectional view on the line 22 ofF1g.1 and- I Fig. 3 1s a sectional view on the line 3-3 of Fig. 1.

ses and to eliminate practically all.

Specification 01 Letters Patent. Patented Aug. 23, 1921, Application filed larch 17, 1920. Serial No. 868,480. I

- The same numerals will identify the same and beingl provided with an outlet nozzle 5,

leading t rough the bottom of the casing 4 at one end in proximit to the down-turned,

end 2 of the pipe 1. T e casing 4 is entirely closed except for the outlet nozzle 5, and it is of larger diameter than the pipe 1, so as to inclose a chamber which surrounds the discharge pipe and the interior of the discharge pipe 1 can communicate with this chamber through a number of openings or apertures 6. In operation the exhaust gases flowing from the engine are .expanded when they reach the casing 4:, and enabled toescape into the atmosphere, part1 through the outlet 3 at the discharge end 0 the pipe 1, and partly through the nozzle 5, leading from the casing 4. Some of the gases flow through the openings 6 into the casing 4, and then reachrzthe atmosphere by way of the nozzle 5, and the remainder of the exhaust gases pass into the atmosphere by way of the exhaust pipe direct, partly by way of the outlet 3, and partly by way of some additional openings 7 which are located in the bend of the'pipe at' 2. The efl'ect'of the openings 6 is to enable the gases to expand as soon as the reach the casing 4, and the portion which ows into the casing 4 will be very little above the pressure of the atmosphere when the nozzle 5 is reached, and the remainder of the gases will be similarl reduced in pressure by the time the reac the openings 7 and the outlet 3. e may provide deflectors 8 on the inside of the bent.

any convenient position forward of the discharge end of the exhaust pipe 1, and can be secured to the pipe 1 in any suitable way.

The number and size of the holes 6 will of course be var ed according to clrcumstances,

I. and the particular'type of the engine with which the pipe 1 is connected, and we may also make the holes round or square, or m the form of slits, or give them any other desirable shape. We have found in practice that a mufller of this construction not only permits the exhaust gases to expandto such a degree that as they pass out into the air through the outlets 3, 5 and 7 the engine is rendered quite noiseless, but also causes the entire disappearance of back pressure in the engine cylinders. With most mufflers the back pressure due to the exhaust causes a very appreciable loss of power, while with our mufiler this loss of power, due to back pressure created by the exhaust gases, is entirely avoided.

The mufller herein set forth can be made out of any convenient material, such as sheet metal and the baffle plates 8 can be provided bycutting the pipe 1 in the bent portion 2, and then forcing the metal at the points where the cutting is effected inward. In

this way both the openings and the deflectors 8 can be obtained by practically a single operation.

Having described our invention, what we believe to be new and desire to protect by Letters Patent of the United States is:

1. A mufiler for exhaust gases comprising an exhaust pipe having'an outlet and a casing surrounding said pipe, and pipe passing through the casing but communicating with the interior of same, said casing having an outlet for the exhaust gases adjacent the outlet of the pipe, whereby the gases pass from the exhaust pipe through both said outlets without substantial change of direction, and back pressuredue to said gases, is eliminated.

2. A mufiler for exhaust gases, comprising an exhaust pipe having an outlet, a casing surrounding said pipe, the pipe passing through the casing,'and having openings to enable the pipe to communicate with the inside of the casing, said casing having an outlet adjacent the outlet of the pipe, the exhaust pipe also having openings between the casing and its own outlet, and deflectors in the pipe adjacent each of said last mentioned openings, whereby back pressure due to the exhaust gases, is eliminated and the gases escape through both said outlets without substantial change of direction.

Signed at New York, in the county of- New York, and State of New York, this 6th day of March, A. D. 1920.

HARRY F. DUBBEN. FRANK B. EASTON. 

